Professor Lueptow's current research interests are in three areas: 1) Modeling, simulation, and experiments on the segregation and mixing of bi-and poly-disperse granular materials, both spherical and non-spherical, in quasi-2D and fully 3D geometries; 2) A dynamical systems approach to mixing by "cutting and shuffling," particularly as applied to granular materials; 3) Molecular level simulation of transport processes in polymeric nanofiltration and reverse osmosis membranes.